The present invention relates to an improvement in a device for pulse current action on the central nervous system.
The invention is applicable for carrying out a prescribed anesthesia and treatment program, for example, in the course of child delivery.
There is known a device for pulse current action on the central nervous system (U.S. Pat. No. 3,989,051), wherein current pulses are applied to a patient through electrodes, i.e., a cathode attached in the forehead area and an anode attached in the neck area, under the mastoids, in order to produce the second level of the first stage of general electroanesthesia in the central nervous system of the patient. Current pulses are supplied from a unit for rhythmic action by current pulses on the central nervous system, a unit for adjusting the duration of current pulses or an intermittent analgesia unit, a switch, a unit for adjusting the amplitude of current pulses and a mean current intensity indicator, which makes it possible to produce the second level of the first stage of general electroanesthesia without any side effects on the patient. The units are connected in series. The application of current pulses is discontinued by a patient protection unit if the amplitude of current pulses is in excess of a preselected value.
In this device, the output of the patient protection unit is so connected to the input of the power unit that said patient protection unit disconnects the power unit from the unit for rhythmic current pulse action on the central nervous system, the unit for adjusting the duration of current pulses, the intermittent analgesia unit and the unit for adjusting the amplitude of current pulses, if the amplitude of current pulses is above a preselected value.
In order to mitigate pain in the course of electroanesthesia, the operation of the device must be discontinued by disconnecting the power unit from the above-mentioned units, which discontinues the current pulse action on the central nervous system, sharply reduces the effects of electroanesthesia, and prevents the use of the second level of the first stage of general electroanesthesia necessary for anesthesia and treatment.
It has been established that while performing anesthesia and treatment with current pulses, it is necessary to stabilize the second level of the first stage of general electroanesthesia once it has been achieved, without any further increase in the mean current intensity in the patient circuit even in case of a change in the impedance at the points where the electrodes are attached, which may be caused by a change in the functional state of the central nervous system.
It is an object of the present invention to improve the device for pulse current action on the central nervous system to ensure a desired pulse action level for each patient in accordance with a prescribed anesthesia and treatment program.
It is another object of the invention to improve the device for pulse current action on the central nervous system to permit the limitation of the mean current intensity in the patient circuit without discontinuing operation of the device in case of a reduction in the impedance in the electrode areas, caused by a change in the functional state of the patient's central nervous system.
The foregoing objects are attained by providing a device for pulse current action on the central nervous system, wherein current pulses are applied to a patient through electrodes, i.e., a cathode attached in the forehead area and an anode attached in the neck area, under the mastoids, in order to produce the second level of the first stage of general electroanesthesia in the central nervous system of the patient. In the device of the invention, current pulses are applied to the patient from a number of series connected units which include a unit for rhythmic current pulse action on the central nervous system, an intermittent analgesia unit or a unit for adjusting the duration of current pulses, a switch, a unit for adjusting the amplitude of current pulses and a mean current intensity indicator, which makes it possible to produce the second level of the first stage of general electroanesthesia without any side effects on the patient. The second level of the first stage of general electroanesthesia is stabilized by a patient protection unit. The device of the invention further includes a current pulse preamplification unit whose input is electrically coupled via the switch to the output of the unit for adjusting the duration of current pulses so as to produce the second level of the first stage of general electroanesthesia, or to the output of the intermittent analgesia unit so as to counteract growing pain, and a unit for adjusting the value of an additional constant component, whose input is connected to the output of a power unit, which makes it possible to reduce the impedance at the points where the electrodes are attached in the forehead and neck areas. Other inputs of the current pulse preamplification unit and the unit for adjusting the value of the additional constant component are connected to the power unit and the outputs of the patient protection unit so as, while acting with current pulses on the central nervous system, to limit the level of general elctroanesthesia in accordance with an anesthesia and treatment program prescribed for each patient. The outputs of the units are connected to the inputs of the unit for adjusting the amplitude of current pulses. The patient protection unit is connected to the power unit. The input of a current pulse amplitude indicator is connected to one of the outputs of the unit for adjusting the amplitude of current pulses.
The proposed device for pulse current action on the central nervous system makes it possible to perform current pulse anesthesia and treatment during prolonged periods of time, and ensures complete electric safety of the patient and a stable level of general electroanesthesia. The invention makes it unnecessary for a physician to attend to a patient throughout a period of application of electroanesthesia or to control the intensity of current pulse action on the central nervous system of the patient.